Drive axle construction for independently sprung wheels



March 11, 1947. n oos 2,417,325

DRIVE AXLE CONSTRUCTION FOR INDEPENDENTLY SPRUNG WHEELS Filed March 24, 1944 5 Sheets-Sheet l INVENTOR.

130 134 Delmar 5.12005 131 1%133131 By W AZTORNEY Marchl1,1947 DGROOS 2,417,325

DRIVE AXLE CONSTRUCTION FOR INDEPFNDENTLY SPRUNG WHEELS Filed March 24, 1944 3 Sheets-$heet 5 INVENTOR. 29. 17751" 5. H005 Patented Mar. 11, 1947 DRIVE AXLE CONSTRUCTION FOR INDE- PENDENTLY SPRUNG WHEELS Delmar G. Roos, Toledo, Ohio, assignor to Willys- Overland Motors, Inc Toledo, Ohio, a corporation of Delaware Application March 24, 1944, Serial No. 527,982

6 Claims.

This invention relates to axles of automotive vehicles and more particularly to an arrangement wherein the driving wheels are independently sprung on the frame,

The invention embraces the provision of avehicle wheel driving means associated with half axles so arranged that each of the driving wheels is arranged for vertical movement independently of the other.

The invention is inclusive of an arrangement wherein the housings for the wheel driving shafts are articulately connected together substantially at the longitudinal center line of the vehicle so as to obtain a maximum radius of oscillation for the drive wheels so as to minimize the amount of wheel tread variation.

An object ofthe invention resides in an arrangement of driving means for an automotive vehicle in which the unsprung weight is greatly reduced over the conventional type of solid axle.

The invention is inclusive of an arrangement of driving means for vehicle wherein the axles are articulated about a common center and wherein the differential mechanism and drive gearing are associated with one of the wheel driving shafts in such a manner that vertical movements of the driving gear and differential mechanism are minimized and wherein a large proportion of the weight of said mechanisms is sprung weight.

Another object of the invention resides in an arrangement of this character wherein the driving torque reaction is transmitted to the vehicle frame through one of the springs connected to one of the axle constructions.

Another object of the invention resides in the provision of an independently sprung axle construction in which components of the wheel driving means are articulated through the use of a single universal joint. 2

Still another object is the provision of novel means for articulately connecting the axle housing together for oscillation about a common center in a manner wherein the components of the oscillating joint structure are reduced to a mini'mum.

Further objects and advantages are within the scope of this invention such as relate to the ar-' rangement, operation and function of the related elements of the structure, to various details of construction and to combinations of parts, elements per se, and to economies of manufacture and numerous other features as will be apparent from a consideration of the specification and. drawing of a form of the invention, which may be preferred, in which:

Figure 1 is a top plan view showing one form of my invention;

Figure 2 is a side elevational view showing thethe axles together;

Figure 6 is a view showing the configuration of the components making up the ball joint;

Figure '7 is a view illustrating the relation of the components of the joint in extreme angular positions.

While I have illustrated the arrangement of my invention as adapted for a rear wheel drive of avehicle, it is to be understood that my invention may be utilized as a front wheel drive or a four wheel drive vehicle without departing from the spirit of the invention.

Referring to the drawings in detail, the frame of the vehicle with which I have illustrated my invention is inclusive of side rails or frame members H3 and II joined together at their rear extremities by means of a transverse member l4 andreinforced by means of a diagonally arranged strut l5 which is secured to the side rails l0 and II by means of rivets l6 and to the transverse bar 14 by rivets ll. The side rails Ill and II are also. joined together by means of hollow tubes or members 20 and 2i having their extremities welded or otherwise secured to the side rails.

Arranged beneath the frame members 10 and H are brackets 22 and 23 which are secured to the frame by rivets 24, each bracket having openings therein to receive a bolt 25 which forms a connection for an eye formed at the forward extremity of the upper leaf of each of the leaf spring assemblies 26 and 26' arranged at either side of the vehicle and beneath the frame members l0 and II. Brackets 28 and 29 are secured by rivets 351 to the rear portions of the frame members It! and H as particularly shown in Figure 2, the depending side walls of brackets 28 and 29 having aligned openings to receive shackle bolt portions 3! ofspring shackles 32, the lower extremities of the spring shackles 32, being formed with bolt portions 34 passing through the eyes formed at the rear extremity of the upper spring leaf of each spring assembly.

Positioned substantially centrally of the frame construction is a bracket or support 3! having a 'uniplanar horizontally arranged portion 38 and upwardly extending projections 39 welded or otherwise secured to the tubes 20 and 2| as at ii]. In the embodiment illustrated, the uniplanar portion 38 of member 31 is arranged to carry or support members 42 and 43. The members or supports 62 and 43, and the uniplanar portion 38 of bracket 31 are formed with aligned openings to receive bolts 44, the upper ends of the bolts receiving castellated nuts 45 to secure members 42 and 43 in fixed position with respect to and supported upon the frame construction. Cotter keys 46 are utilized to prevent removal of the nuts 45. The interior walls of members 42 and 43 when assembled together provide a partial spherical configuration, which forms part of an articulated connection between the axle housin constructions, this arrangement being hereinafter more fully described.

In the arrangement of my invention as illustrated, the engine or prime mover (not shown) is arranged forwardly of the rear driving wheels. The powerof the engine is conveyed through a transmission construction (not shown) to a propeller shaft 49, the latter being joined by means of a'universal joint or coupling 50 to a flanged fitting 48 carried upon a comparatively short driving or pinion shaft 5|, the latter having a pinion 52 formed on the end thereof. The pinion shaft 5| is suitably mounted for rotation in antifriction bearings 53 disposed in a hollow projecwelded in fixed position to member I39 as at I40. 7 The housing 55 is formed with a projecting bearing 95 or other suitable antifriction bearing 7 means for revolubly supporting the shortshaft tion 54 formed on a differential and driving gear housing 55. The driving pinion 52 is enmeshed with a driven or ring gear 58,, the latter being secured to a differential casing or spider 59 by means of stud bolts 60. The differential casing 59 is journalled in bearings 6I and 62 mounted in recesses in the housing 55. The differential mechanism is inclusive of a stud shaft 63 upon which is revolubly mounted bevel pinions 64 and 65 which are in mesh with bevel gears 61 and 68. Gear 61 is feather-keyed upon the splined extremity 69 of an axle shaft or live axle I0, while gear 68 is similarly feather-keyed upon the extremity of a shaft I2, in alignment with the axle shaft I0. The opening in the rear of the housing 55 is closed by means of a cover 55 retained in place by means of cap screws 51.

Housing 55 enclosing the driving gear and differential mechanism is formed, with a hollow lateral extension I4 which receives the inner end of an axle or axle housing I5, the parts being welded together as shown at I6. The outer extremity of theaxle I5 is enlarged to accommodate an anti-friction. bearing means I8 upon which is journalled a shaft or live axle I0. The axle shaft I0 is formedwith tapered portion 80 adapted to receive a hub 8I, the latter supporting' a wheel 82 secured thereto by means of bolts 83. The hub 8| is retained on the tapered portion of the axle shaft by means of a securing nut 84. The wheel 82 is provided with a rim 85 carrying a pneumatic tire 86. Welded to the axle I5 is a spring pad 8! which forms a seat for the leaf spring assembly 26, the latter being secured to the spring seat by means of U-shaped bolts 88. The legs of the U-shaped bolts 88 extend through openings in a plate I30, nuts 89 being threaded onto the U-shaped bolts serving tohold the plate I30 and the spring assembly rigidly to the axle 15. Plate I30 is formed with depending flanges I3I having aligned openings to receive a pintle I32 which is welded to the flanges as at I33. Pivoted upon the pintle I32 is a member I34 formed upon the lower end of an element I35 forming part of a hydraulic shock absorber of conventional design. Another ele- ',ment I36 of the shock absorber construction, which istelescopically arranged with respect to .element I35, has a projection I31 pivoted upon a pin'or pintle I38. The pin I38 extends through openings in a channel shaped bracket I39 welded to the side'of the frame rail I0, the pin 138 being I2. Shaft I2 is formed at one extremity with a configuration 96 forming one element; of the universal joint construction. Another element 9! of the universal joint arrangement is provided with a hub portion 9.8, which is splined upon the extremity of an axle shaft I00 to the outer end of which is secured a vehicle wheel I0l. Axle shaft I 00 is surrounded by an axle or housing I02 which'is enlarged at its'outer end to-accommodate an antifriction bearing I8 of the same construction'as bearing I8; Thus, rotation of shaft I2 is communicated to axle shaft I00 through the medium of the universal joint con struction 96-9I. As the universal joint construction illustrated is of conventional design it is believed unnecessary to describe it in further detail.

Axle shaft I00 carries at its extremity a road wheel with rim and tire assembly as is carried by road wheel 92. A spring pad 81' is welded to the axle or axle housing I02 to which is secured a leaf spring assembly 26" of identical construction with leaf spring assembly 26. This arrangement is also provided with a hydraulic shock absorber construction I35'-I36 which is connected between the leaf spring assembly 26' and the frame rail II in the same manner that shock absorber I35--I35 is connected to leaf spring assembly 28 and frame side rail I0.

In the arrangement of my invention as illustrated, the center of the universal joint is substantially in the longitudinal center plane C-,-C of the vehicle. The axle constructions are arranged for limited oscillatory movement about the centerof the universal joint construction 96-91. To this end the member 9| is formed with a partial spherical shaped portion I05. Welded to the inner end of the housing I 02 as at 99 is a member I06 which is formed exteriorly into two partial spherically shaped portions I08 and I09 of different radii. The exterior spherically shaped surfaces of portion I05 and I08 are of substantially the same radii and members 42 and 43 forming a, support are formed with interior spherically shaped surfaces H0 and I I I of a dimension to slidably or oscillatably receive the exterior surfaces I05 and.I08 and form a spherical seat therefor. The radius of the interior wall I I2 of portion I05 and the radius of the exterior surface of portion I09 are such as to coincide or slidably fit together.

It is to be noted that the .angles through which theaxle construction .oscillate in, a vertical direction are limited by the amount of relative oscillatory movement of portion I09 withrespect tothe'portion I05. Oneofthefeatures of the present invention resides in the novelarrangement of fabricating the ball joint of this character with a minimum number of parts or elements. In order to assemble portions I05 and I08 in the present construction, the parts are brought into preliminary contact as illustrated in Figure 7 and both portions of the ball configuration inserted in the half spherical recess formed inthe support 42. vWith the parts in this position, member '43 is then moved to proper position andis secured to member 42 by means of the studs 44. The member 43 isprovided with a partial spherical surface also engaging the spherical surfaces I05 and N18 to secure members 9| and I06 in definite articulate relationship. It should be noted that due to the particular construction of the ball shaped configurations, an annular space H5 is provided which accommodates independent oscillatory movements of each of the axles or axle housings i5 and I02, the center of oscillation being about the center of the coupling formed by the un versal joint 96-9'l.

The differential mechan sm, driving pinion, ring gear and universal joint mechanism it-4N are lubricated by lubricant contained within the housing 55, the lubricant being permitted to pass through the'interstices between the needles of bearing $35 to reach the interior of the ball joint -configuration. Openings l I! are provided in portion I09 in order to admit lubricant to the spherical surfaces of portions H05, H38 and the interior spherically shaped surfaces of supporting members l2 and 43 so as to adequately lubricate all relatively movable elements of the ball joint. Lubricant seals I I8 and l i9 prevent the escape of lubricant from the housing 55 and the ball joint construction. The exterior portions of supports :32 and 43 are formed with annular grooves to receive dust caps i213 and 12! of flexible material to accommodate relative movements of the axles, the caps serving to prevent the ingress of dirt or other foreign matter into the ball joint construction.

The operation and action of the vehicle driving means and axle arrangement of my invention is as follows: Each of the wheels 85 and llli being connected. through the axles or axle housings l5 and H12 and other elements hereinbefore described, to the ball configuration arranged within the supports 42 and d3 oscillate about the center of curvature of the interior surface of supports 32 and 53. It should be noted that axle housing 15, drive gear and difierential housing 55 and member 9! are all fixedly secured together so that these elements form, in efiect, an integral wheel supporting means or axle oscillating about a point disposed centrally of the vehicle, the distance of each wheel from the center of its oscillation being substantially the same.

The arrangement of my invention hereinbefore described permits vertical movement of one driving wheel independently of the other, which is a vital factor enhancing the riding comfort of the vehicle. During vertical movements of one or both of the driving wheels,'there is a variation in the point of contact of the tread of the wheels upon the roadway due to the fact that the wheels ar fulcrumed or hinged for oscillation about a common center. I have found that this is advantageous in that it tends to distribute the wear on the tires over a wider peripheral area thereof. Furthermore, I have found that in the practical operation of a vehicle embodying the invention, there is little or no scufiing or scrubbing of the tires upon the roadway surfaces apparently for the reason that while the point of contact or tread of a driving wheel is changing laterally, the vehicle is in motion, and the tires are in rolling engagement with the roadway. Thus, if roadirregu'arities cause vertical movement of the wheels with consequent variation in the tread, the path of contact of the tire on the roadway may be out of parallelism with the direction of movement of the vehicle, but as this changing contact is a rolling action of the tire, very little, if any, lateral scufling is encountered.

The differential housing 55 and parts contained therein as well as the end portion of the propeller shaft, being fulcrumed about the center of oscillation of the bal1 joint connecting the axle housings, provides an arrangement whereby a large proportion of the weight of these parts or elements is carried upon the supporting structure 42-43. This construction, therefore, minimizes the unsprung weight carried by the tires and wheels, thus enhancing the ride of the vehicle. As the differential housing is fulcrumed quite closely to the center of oscillation of the axles, the vertical movement of the housing and the propeller shaft connected thereto, is very small as compared to the vertical movement of the driving wheels, the ratio of movement being in proportion to the distance of the housing from the fulcrum or center of oscillation of the swinging axles as compared to the distance of the driving wheel 86 from the fulcrum. By minimizing the vertical movement of the propeller shaft 49, the vehicle body may be lowered with a consequent lowering of the center of gravity, thus enhancing the roadability of the vehicle.

As the leaf spring assemblies are securely and rigidly fastened to the spring seats Bl and 31' carried by the axle housings l5 and Hill, during each increment of deflection of the leaf spring assemblies in a vertical plane there is attendant a twisting or torsion movement of the main leaf of each spring assembly and to a certain degree a twisting or torsion of the other supporting leaves in each assembly. Thus it will be seen that during vertical movements of the driving Wheels, each leaf spring assembly is subjected to a compound action of deflection in a vertical plane and torsion or twist about a longitudinal axis which secures several important advantages, enhancing the ride of the vehicle. In the first instance, the spring rate, i. e. the amount of defiection per increment of weight imposed upon the spring is a variable factor, so that as the load upon the spring is increased, the amount of deflection per unit increment in load proportionate- 1y decreases. Thus, in eifect, with an increased load upon the vehicle springs, the latter becomes stiffer and its resistance to deflection is increased. Th compound spring action of vertical deflection combined with longitudinal torque or twist eliminates any natural period of vibration of the spring. This I have found to be very important as affecting the ride of the vehicle because this compound spring action providing a variable rate spring, tends to inherently damp out vibrations, and especially is this true as to rebound or jounce resulting from th reaction of contact of the driving wheels with road irregularities or obstructions. I have found, from a practical application of the invention, that the spring rebound resulting from the vehicle wheel encountering a road obstruction is very quickly damped out and very little, if any, vibratory reaction transmitted to the frame and body soethat a very smooth ride is obtained. I

In the form. of my invention illustrated, the torque reaction'of the arrangement is absorbed by the spring assembly 26 connected to the axle tube '55, as there is no torque resistant connection between axle housing l5 and axle housing Hi2. This makes for a very flexible drive as the reaction is all taken by only one of the spring assemblies. The brake reactions are absorbed, however, by both leaf spring assemblies 28 and 26'.

It is apparent that, within the scope of the invention; modifications and different arrange ments may be made other than is herein dis closed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.

I claim:

1. In an automotive vehicle, a frame; a pair of drive wheels; wheel supporting means for each of said drive wheels arranged for independent vertical movements with respect to each other; axle shafts for each of said wheel supporting means; a ball joint; said wheel supporting means being articulately connected together through said ball joint for limited oscillatory movement about a common center; the center of said ball joint lying in a central longitudinal plane through the vehicle; a difierential housing forming a part of one of said wheel supporting means; driving means for said differential mechanism and said axle shafts including a propeller shaft extending substantially at right angles with respect to said wheel supporting means; a leaf spring rigidly secured to each of said wheel supporting means and to said frame; said leaf springs being subjected to compound action of deflection and torsion during vertical movements of said drive wheels.

2. In an automotive vehicle, a frame; a pair of drive wheels; wheel supporting means for each of said drive wheels arranged for independent vertical movements with respect to each other; axle shafts for each of said wheel supporting means;

a ball joint; a support therefor having curved interior surfaces slidably engaging exterior spherical surfaces of the ball joint; said ball joint support being rigidly connected to said frame and arranged whereby the center of said ball joint lies in a central longitudinal plane through the vehicle; said wheel supporting means being articulately connected together through said ball joint for limited oscillatory movement about a common center; a differential housing forming a part of one of said wheel supporting means; drivin means for said differential mechanism and said axle shafts including a propeller shaft extending substantially at right angles with respect to said'wheel supporting means; a leaf spring secured to each of said wheel supporting means and to said frame; said leaf springs being subjected to compound action of deflection and torsion during vertical movements of said drive wheels.

3. In'combination, a vehicle frame; a pair of half axle elements arranged for independent vertical movements with respect to each other; road wheels carried by said half-axle elements; spring means disposed between said frame and said half-axles; means for articulately joining said half axle elements together including interior and exterior curved surfaces formed on one of said elements; the second axle element having portions whose exterior surfaces are of curved configuration and of different radii; the curved surface of said second mentioned axle element arranged to slidably fit within the interior curved surface of said first mentioned axle element;

and supporting means secured to said vehicle frame and arranged for slidable engagement with exterior curved surfaces of both of said elements for retaining the same in articulated relationship.

4. In combination, a vehicle frame; a pair of axle elements arranged for relative vertical movements with respect to each other; road wheels carried by said axle elements; spring means disposed between said frame and said axle elements;

8 a means for oscillatably joining said elements together including a hollow partial spherically shaped interior and exterior configuration formed at one end of one of said axle elements; the second of said axle elements having a portion configurated with a pair of spherically shaped surfaces of different diameters; the larger of said surfaces being of the same diameter as the exterior spherical surface on said first mentioned axle element; the lesser of said spherical surfaces being arranged to slidably fit the interior spherical surface of said first mentioned axle element; n r l iv ly stationary means secured to 'said frame and engageable with spherically shaped surfaces of each of said axle elements for retaining the latter inoscillatable relation.

5. In an automotive vehicle, a frame having side rails and a transversely extending member; a differential housing; said housing having a portion secured thereto and forming an element of a ball joint; a hollow axle having a portion forming another element of the ball joint; means carried by said transversely extending frame memher for securing the elements of said ball joint in articulated relationship whereby the center of oscillation of said ball joint lies in a central longitudinal plane through the vehicle; a second hol low axle rigidly connected to said housing; road wheels mounted upon said axles, leaf springs arranged each side of said frame and having their extremities pivotally connected to said frame side rails; the mid portions of each of said leaf springs being rigidly secured to one of said hollow axles.

6. In an automotive vehicle, a frame having side rails and a transversely extending member; a housing; said housing having an integral portion forming an element of a ball joint; a hollow axle having a portion forming another element of the ball joint; means including said housing carried by and disposed centrally of said transversely extending frame member for securing the elements of said ball joint in articulated relationship; a second hollow axle rigidly connected to said housing; leaf springs arranged at each side of said frame and having their extremities pivotally connected thereto; the mid portions of each of said leaf springs being rigidly secured to one of said. hollow axles; driving shafts contained within said hollow axles; differential mechanism contained within said housing, one of said shafts being connected to said differential mechanism, a universal joint positioned within said ball joint, and connected to the other driving shaft; a shaft connecting said universal joint with said differential mechanism, and road wheels secured to each of said driving shafts.

- DELMAR G.'R O0S.

REFERENCES CITED The following references are of record in the file of this patent: i

UNITED STATES PATENTS 

